Hi everyone! It's been a long time since I've been here but here I am again and I'm hoping some of you can help me out with the issue I'm having with my van!
It's a 1979 Dodge B300 extended cargo van. It has a 360 v8 2bbl engine...

So here's the deal... I recently started driving my van as my daily driver because of issues with my other vehicle and noticed the voltage is very high!
All the following readings were taken at the battery!
It idles at around 13.4v and goes up to 16.5 - 17v when the rpm's are increased!
With the headlights on it idles at 13.3v and goes up to 17v at high rpm's...
With just the blower motor on it idles at 13.0v and when rpm's are increased it goes up to 15.5 and slowly keeps going up...
With the lights and blower at the same time it idles at 12.9v and when rpm's are increased it goes up to 13.5v and slowly goes up....

I've cleaned and secured the connections on the back of the alternator! I did NOT check the connection between the alternator body and mounting bracket attached to the engine!
I cleaned and secured the ground connection on the voltage regulator to the firewall! I'm not really sure how to check the regulator with a voltage meter but here's what I did...
The regulator has two wires, red and green... The red wire connects to the center pin and that's the pin I attach the red probe from the multimeter and the black probe goes to the other pin at the top...

Here are the resistance settings and readings:
20M 9.5
2M 1.395
2K 1.965

With the probes reversed:
20M 9.13
2M 1.465
2k 1.165

These three settings on the multimeter are the only ones that gave me readings!
I also noticed when I removed the regulator from the firewall that the silicone/resin is completely detached from the metal body all the way around the edge and a bunch of sand poured out!!! I'll proved pictures in a little while, it's raining and I don't have a garage... 😕

It may be pretty clear that the issue is the regulator but I'm still learning and not 100% sure...

What you need to do is read the voltage on the blue wire wire to the regulator. It should be within .1-.2v of the battery voltage. If not then the regulator is seeing a low system voltage and is upping the output of the alternator to compensate.

There's only a red wire and a green wire to it...
With the regulator detached the battery reads 14.4v...
Both the red and green wire share the same reading! Both are showing 13.0v and seam to increase by 0.1v every 20 seconds...

Is anyone seeing how much sand is in this regulator?!?! That's not even half of it!!!! How does that even fit in there?!?! Does this have anything to do with the issue at hand???

Yup. It says made in China, that's all I need to see to say it's probably a POS

Yeah I have a tendency to buy the cheap stuff sometimes! I bought that regulator about 10 years ago off ebay probably and I'm sure it was the cheapest one I could find!
I just ordered an ACDelco unit off Amazon! I'm hoping it's just the regulator causing the issue!

Check and clean as needed all of your grounds, the battery is a chemical based storage devise that makes the voltage that the vechicle runs on. The current flow from all batteries flows out the negative terminals into the system and returns through the positive side of the battery
If the grounds are not good it may lead to overcharging

If your 12v supply to the regulator is 1.4v below battery voltage that is your issue.

The direction of current flow is nice to know on a theoretical basis. In real life it matters not. You need clean, solid connections on both the positive and negative sides, regardless.

So what's the solution?? What can be causing that??
Bad ground? Bad cable?

Dirty connections, loose connections. including the ignition switch. I don't have any truck manuals so I can't say, specifically.

ok, lets start the trouble shooting.
with the van off
positive side of the battery to negative side of the battery reading=
with the key in the run position but the engine off

the ballast resistor should have 2 connectors on it.
what is the highest voltage reading you get using the battery negative and the ballast as the postive?
you can also unplug the vr and check the pin with voltage using the case as ground when it is bolted up to the body, what voltage do you get there?

if either of this is different than your first reading at the battery, you need to start checking a few more things.
does the voltage at the vr change if you use the battery ground instead of the case as ground?
if not then you have to start chasing the positive side back.
the positive passes through the bulkhead connector 3 times.
you can bypass this temporarily to see if your problem goes away by running a wire directly from the pos of the battery to the highest voltage side of the ballast resistor.
this will back feed the system with battery voltage directly so it isn't passing through the bulkhead.

start the van and check charging again with the bypass installed.
if that works, then it is a bad connection in the bulkhead that needs to be cleaned or replaced.
you will have to follow the line or check the wiring diagram to see which ones need to be checked.

This will work.

What I might add is if you determine the problem is at the bulk head connector, clean all the wire connectors, not just the wires to the charging system. If those connections are dirty and making poor contact, so are the rest of the connections in the bulk head connector.

The sand you are seeing in the regulator might be caused by the dust/sand blowing around in the air where then van has been parked.

Awesome! I'll get out there and perform these tests after I've had my coffee and I'll be back with the results!
It's interesting you bring up the bulkhead because yesterday it was raining and the seal around the engine compartment that's supposed to seal the hood doesn't do a very good job of keeping the water out! Water was dripping and splashing all over the bulkhead!!! That seal is something I've been meaning to fix! Well, it may or may not be the problem but I'll find out in a couple of hours!

I tried in the past to pull the wires out of the bulkhead connector to clean them with no success
! Not sure if I just gave up after a few minutes but I may need to make a tool or something because those connections are very solid as far as I remember!
I live in Arizona and we don't have that type of sand where I live! It's more of a silty clay not beach sand like the stuff from the vr!!!! I thought that was kinda weird! Maybe it's from when I lived in California? Or most likely from driving the I40??? The majority of the miles on it are from driving either on the 101 in Cali or I40 in Arizona... Whatever the case it was an interesting find and surprised if the vr is still working properly, which I'm still not sure of! I wouldn't be surprised if more than one thing is wrong with it though! Last time something happened the driveshaft fell off at the diff and the distributor broke at the exact same time!
Anyway, I'll get out there and perform those tests and brb!

I had a 79 Volare years ago that was overcharging.
A shorted wire in the diagnostic port was full fielding the alternator. Very frustrating till I found out what was wrong.

That "sand" is the filler inside the unit.

You might think your connections are clean, the voltage checks say otherwise.

This might help. https://www.youtube.com/watch?v=vEL-99w5HRU

Ok so I did the checks and it's a little confusing but I'll try my best to lay out the info so it makes sense!
First off the ballast resistor I have is the one with four connectors(pictured)! To show the values if each connector I'll draw diagrams and post the pictures...

So the first check I did was the battery reading, multimeter direct to the pos and neg terminals... It read 13.0 volts with no key!
After putting the key in the ignition and having it in the ON position for about ten mins the voltage increased to 14.4 and kept increasing by 0.01 volts every 7 seconds! By the time I was done with the checks the battery read 18 volts and that's without having turned the engine over once! I've never had a battery increase in voltage like that with only having turned the key to the ON position for a few minutes! It's a brand new battery! Could the battery be the problem??? Anyway, thought that was a strange and important detail!

I'll keep going with the readings I found...
I drew diagrams and test results for all the tests on a dry erase board and the pictures I post is where all the info is going to be so please look at and read everything in the pictures thoroughly please!

Here's the results for the Voltage regulator tests...